Motion transmitting apparatus

ABSTRACT

A transmission includes means driving a pulley connected to a plurality of crank arms which in turn each engage an elongated cam slot formed within separate pivotable rock levers. As the pulley is driven the connected crank arms revolve to oscillate the rock levers such that individual connecting rods likewise carried by the rock levers are caused to reciprocate and thereby drive a crank shaft joined to their free ends.

United States Patent 1191 Sanderson Mar. 25, I975 MOTION TRANSMITTINGAPPARATUS [22] Filed: Apr. 16, 1974 [21] Appl. No.: 461,364

[52] US. Cl. 74/66 [5 I] Int. Cl. Fl6h 21/14 [58] Field of Search 74/66,65

[56] References Cited UNITED STATES PATENTS 124,829 3/1872 Langdonu...74/65 1,585,929 5/1926 Loessel 74/65 FOREIGN PATENTS OR APPLICATIONS102,171 8/1925 Austria 74/66 Primary Examiner-Wesley S. Ratliff, Jr.Attorney, Agent, or Firm-Emory L. Groff, Jr.

[57] ABSTRACT 9 Claims, 5 Drawing Figures .1 1 MOTION TRANSMITTINGAPPARATUS This invention relates generally to motive translatingmechanisms and more particularly to an improved apparatus fortransmitting motion by means of a unique arrangement including aplurality of pulleys, crank arms and reciprocating levers.

Transmission devices for conveying power from a driving source to adriven member and which incorporate rotating cranks and reciprocatinglevers are generally well known. In many such prior devices a noteworthyshortcoming has been the excessive drag or frictional force which hasbeen produced during operation of the apparatus which, coupled with anoften erratic motion between certain of the moving components, resultedin a not too acceptable device. By the present arrangement a uniquecombination of rotating cranks and oscillating or rocking levers isincorporated in combination with a novel floating connection between thecrank arms and oscillating levers which has been found to yield a vastlyimproved operating mechanism.

Accordingly, one of the primary objects of the present invention is toprovide an improved motion transmitting apparatus incorporating aplurality of rotating cranks engaging, by a floating connection, with aplurality of rock levers which in turn produce a reciprocating motion ina plurality of connecting rods leading to a driven power shaft.

Another object of the present invention is to provide in a motiontransmitting apparatus a floating connection between a rotating drivepin and an oscillating rock lever which includes an elongated cam slot.

Still another object of the present invention is to provide an improvedmotion transmitting apparatus including a plurality of adjacentsub-assemblies, each of which includes a rotating crank arm engaging, bymeans of a floating connection, an oscillating rock lever and whereinthe crank arms are arcuately out of phase with one another.

With these and other objects in view which will more readily appear asthe nature of the invention is better understood, theinvention consistsin the novel construction, combination and arrangement of partshereinafter more fully described, illustrated and claimed.

A practical embodiment of the present invention is shown in theaccompanying drawing, in which:

FIG. 1 is a side elevation of the motion transmitting apparatus of thepresent invention.

FIG. 2 is an end elevation of the structure shown in FIG. 1.

FIG. 3 is a top plan view of the structure of FIG. 1.

FIG. 4 is an enlarged partial top plan view taken along the line 4-4 ofFIG. 1.

FIG. 5 is a fragmentary side elevation view of the floating connectionbetween the crank arm and rock lever on the reverse side of theinvention as viewed in FIG. 1.

Similar reference characters designate corresponding parts throughoutthe several views of the drawings.

Referring now to the drawing, particularly FIG. 1, the present inventionwill be seen to include a standard or support frame, generallydesignated 1, comprising a plurality of uprights 2 joined at their topsby a crossbeam 3 and which serve as a support or mounting means for themotion translating components of the apparatus. At least a pair of theabove described standards are provided in a spaced apart manner as shownin FIG. 2 and secured to the top of each cross-beam 3 is a bearing mount4 having a single longitudinal drive shaft 5 journaled therethrough andextending laterally beyond the outer limits of each of the bearingmounts 4. Keyed to the drive shaft 5 between the two bearing mounts 4 isa large diameter intermediate pulley 6 which is adapted to be rotated bymeans of a drive belt 7 receiving its motive force from a small drivepulley 8 driven by an electric motor 9. This motor may be mounted upon asupport 9 or otherwise secured to a suitable platform extending from theframe 1.

Rigidly attached to the distal portions of the drive shaft 5 are a pairof crank arms It) each of which is of a substantially lesser length thanthe radius of the pulley 6. The inboard end of each crank arm 10 issecurely I affixed to the drive shaft 5 such that the two crank armswill be mounted out of phase with one another and preferably aredisposed to define a angle therebetween as shown most clearly in FIG. 1of the drawing. Carried by the free rotating end portion of each crankarm 10 is a drive pin 11 shown in detail in FIG. 4 of the drawing andwhich includes a reduced-diameter portion intermediate its ends defininga peripheral groove 12 surrounding the hub 13. The groove 12 of eachdrive pin is adapted to engage the upper portion of a rock lever,generally designated 14, by means of a specially configured cam slot l5such that operation of the drive motor 9 will transmit motion by way ofthe small diameter drive pulley 8 and drive belt 7 to the large diameterintermediate pulley 6 which will be understood to result in a rotarydisplacement of each of the drive pins 11 which travel, during onerevolution of each crank arm 10 within the confines of the cam slot 15,from the upper portion thereof to the lower portion thereof and return.A longitudinal slot 10a in each crank arm permits individual adjustmentof the radial positioning of the two drive pins 11.

Each rock lever 14 includes a bar'like element which is pivotallyattached to a fixed pivot shaft 16 carried by the cross member 17forming a part ofthe frame 1. As will be noted, the pivot shaft 16engages the rock levers 14 at a point adjacent the lowermost portion ofthe rock lever such that each rock lever is thereby divided into anupper major section 18 and a lower minor section 19. It will therebyfollow that upon arcuate displacement of the crank arm 10 from the 3oclock position as shown in FIG. 1 of the drawing to the diametricallyopposed 9 oclock position, a significant oscillation of the uppersection 18 of the rock lever will occur which will produce a muchsmaller oscillation of the adjacent lower minor section 19 of therespective rock lever. This minor oscillation of the lower section 19 istransmitted by means of a connecting rod 20 suitably attached to thebottom of the rock lever as by a pin 21, to a driven crank shaftcomprising a power shaft 22 journaled within bearing mounts 23 attachedto the platform 24- which may be carried by the standard 1.

Rotary motion is produced in the driven shaft 22 by means of a crank 25formed at each distal end of the driven shaft 22 and to which the otherend of each connecting rod 20 is connected such that reciprocation ofthe connecting rods 20 will result in rotary motion of the driven shaft22, it being understood that the two cranks 25-25 at opposite ends ofthe shaft 22 are likewise offset from one another 90. The rotatingmotive force delivered to the driven shaft 22 may be utilized to operateany desired device such as by keying a pulley 3 26 to the medial portionof the shaft 22 for driving a belt 27." I

To provide a smooth balanced operation between the various movablecomponents of the present invention it is necessary to incorporate atleast a pair of the crank arms disposed out of phase with one another aspreviously described. Each crank arm 10, rock lever 14,

The formation of the 'cam slot provided in the upper portion of each ofthe major sections 18 of the rock levers 14 is critical in order toproduce the smoothest operation of the present invention. It will beapparent that the longitudinal extent of the slot can be no less thanthe diameter ofthe arc as described by the outermost periphery of thedrive pin hub 13 since the throw of this hub must be accommodated by theslot when in the extreme lower and upper positions present when the hubis at the 6 and 12 oclock locations. Each cam slot 15 includes an uppersection 28 which is curved in one direction with respect to the medialarea of the slot and a lower section 29 which is generally curved in theopposite direction from the medial portion of the slot. A continuousuninterrupted cam surface or track 30 is provided by the edge of theentire cam slot 15 and will be seen to be formed so that a relativelynarrow width is provided in the upper section 28 of the cam slot while asubstantially large width is provided in the lower section 29 of eachcam slot 15. By this arrangement it will be understood that at all timeseach lever is slidably engaged on both its faces by the side walls ofthe groove 12 in the drive pin 11 while on the other hand the peripheryof the hub 13 alternately engages one and both sides of each cam surface30 during each revolution of the pulley 6. The curvature and size of thefront and rear cam slots l515 are generally similar yet do differ fromone another an amount which has been calculated to provide a smoothefficient operation. The upper section 28 of the rear lever will beunderstood to include a smaller width for a greater extent of its lengththan the front lever upper section, as viewed in FIG. 1 while the lowersection 29 of the front lever is provided with a larger width for agreater extent of its length than the rear lever lower section.

1. A motion transmitting apparatus including, a drive shaft, a pulleyfixed to said drive shaft, power means connected to said pulley torotate said drive shaft, a pair of crank arms carried by said driveshaft, a pair of rock levers each having a minor. section and a majorsection with an intermediate pivot point, the free end of each saidmajor section disposed adjacent one said crank arm, each said levermajor section provided with an elongated cam slot bounded by acontinuous cam track, each said cam slot having an upper and a lowercurved section with said lower curved sections defining a substantiallygreater slot width than said upper curved sections, drive means on eachsaid crank arm disposed through one said slot and engaging saidrespective lever cam track whereby rotation of said drive shaft causessaid crank arm drive means to revolve about said drive shaft while saidmajor and minor lever sections oscillate about said pivot point whereby,said drive means engages juxtaposed portions of said upper cam tracksand alternately but one side of said lower cam tracks at a time as saidcrank arm drive means rotates and travels within said slot upper andlower curved sections respectively, a connecting rod having one endpivotally attached to each said lever minor sections, a power shaftincluding a pair of cranks and each said crank joined to the other endof said connecting rods whereby, said oscillation of said lever. minorsections causes said connecting rods to reciprocate and said power shaftto rotate.

2. A motion transmitting apparatus according to claim 1 wherein, saidpulley is disposed intermediate said crank arms, said crank armsprojecting radially from said drive shaft and normal to the center axisof said drive shaft.

3. A motion transmitting apparatus according to claim 1 wherein, saidcrank arm drive means includes a drive pin having a reduced diameter hubconstantly disposed within said cam slot.

4. A motion transmitting apparatus according to claim 1 wherein, thediameter described by said crank arm is substantially one-half thediameter of said pulley.

5. A motion transmitting apparatus according to claim 1 wherein, saidcam slot length is substantially equal to twice the length of said crankarm from said drive shaft to said crank arm drive means.

6. A motion transmitting apparatus according to claim 1 including, astandard provided with two pairs of uprights, each pair joined at theirupper portions by a cross-beam, bearing mounts carried by said crossbeams, said drive shaft journaled within said bearing mounts and saidpulley disposed between said bearing mounts.

7. A motion transmitting apparatus according to claim 1 wherein, thelength of said lever minor section relative the length of said levermajor section defines a ratio of substantially 1:6.

8. A motion transmitting apparatus according to claim 1 wherein, saidconnecting rods are disposed in a plane substantially perpendicular to aline extending through said lever pivot point and said drive shaft.

9. A motion transmitting apparatus according to claim 1 wherein, saidcranks are disposed upon said power shaft to one another.

1. A motion transmitting apparatus including, a drive shaft, a pulleyfixed to said drive shaft, power means connected to said pulley torotate said drive shaft, a pair of crank arms carried by said driveshaft, a pair of rock levers each having a minor section and a majorsection with an intermediate pivot point, the free end of each saidmajor section disposed adjacent one said crank arm, each said levermajor section provided with an elongated cam slot bounded by acontinuous cam track, each said cam slot having an upper and a lowercurved section with said lower curved sections defining a substantiallygreater slot width than said upper curved sections, drive means on eachsaid crank arm disposed through one said slot and engaging saidrespective lever cam track whereby rotation of said drive shaft causessaid crank arm drive means to revolve about said drive shaft while saidmajor and minor lever sections oscillate about said pivot point whereby,said drive means engages juxtaposed portions of said upper cam tracksand alternately but one side of said lower cam tracks at a time as saidcrank arm drive means rotates and travels within said slot upper andlower curved sections respectively, a connecting rod having one endpivotally attached to each said lever minor sections, a power shaftincluding a pair of cranks and each said crank joined to the other endof said connecting rods whereby, said oscillation of said lever minorsections causes said connecting rods to reciprocate and said powEr shaftto rotate.
 2. A motion transmitting apparatus according to claim 1wherein, said pulley is disposed intermediate said crank arms, saidcrank arms projecting radially from said drive shaft and normal to thecenter axis of said drive shaft.
 3. A motion transmitting apparatusaccording to claim 1 wherein, said crank arm drive means includes adrive pin having a reduced diameter hub constantly disposed within saidcam slot.
 4. A motion transmitting apparatus according to claim 1wherein, the diameter described by said crank arm is substantiallyone-half the diameter of said pulley.
 5. A motion transmitting apparatusaccording to claim 1 wherein, said cam slot length is substantiallyequal to twice the length of said crank arm from said drive shaft tosaid crank arm drive means.
 6. A motion transmitting apparatus accordingto claim 1 including, a standard provided with two pairs of uprights,each pair joined at their upper portions by a cross-beam, bearing mountscarried by said cross beams, said drive shaft journaled within saidbearing mounts and said pulley disposed between said bearing mounts. 7.A motion transmitting apparatus according to claim 1 wherein, the lengthof said lever minor section relative the length of said lever majorsection defines a ratio of substantially 1:6.
 8. A motion transmittingapparatus according to claim 1 wherein, said connecting rods aredisposed in a plane substantially perpendicular to a line extendingthrough said lever pivot point and said drive shaft.
 9. A motiontransmitting apparatus according to claim 1 wherein, said cranks aredisposed upon said power shaft 90* to one another.